Never had allergies, I am now in second trimester with a stuffy nose, sometimes itchy eye and sneezy but no other symptoms. Could I have developed allergies. If so is this only during pregnancy?

Possibly. It might be congestion with pregnancy, or just mild viral upper respiratory infection, causing itchy eyes and sneezing, nasal congestion that occurs during pregnancy is common, and more towards the last trimester, relieved after birth, wish you a healthy pregnancy and a healthy baby.
ALLERGIC RHINITIS . PROGESTETONE IS THE HOTMONE OF PRENANCY. One of its many secondary side effects is flaring allergies. Swelling of nasal mucosa/itchy eyes /post nasal drip. You can do nasal irrigation with Neil Med system. Zaditor (ketotifen) Eye Drops and clRitin are all effective.